Source code for xonsh.prompt.base

"""Base prompt, provides PROMPT_FIELDS and prompt related functions"""

import itertools
import os
import re
import socket
import sys
import typing as tp

import xonsh.platform as xp
import xonsh.tools as xt
from xonsh.built_ins import XSH

if tp.TYPE_CHECKING:
    from xonsh.built_ins import XonshSession

    FieldType = tp.TypeVar("FieldType", bound="BasePromptField", covariant=True)


@xt.lazyobject
def DEFAULT_PROMPT():
    return default_prompt()


class _ParsedToken(tp.NamedTuple):
    """It can either be a literal value alone or a field and its resultant value"""

    value: str
    field: tp.Optional[str] = None


[docs]class ParsedTokens(tp.NamedTuple): tokens: tp.List[_ParsedToken] template: tp.Union[str, tp.Callable]
[docs] def process(self) -> str: """Wrapper that gets formatter-function from environment and returns final prompt.""" processor = XSH.env.get( # type: ignore "PROMPT_TOKENS_FORMATTER", prompt_tokens_formatter_default ) return processor(self)
[docs] def update( self, idx: int, val: tp.Optional[str], spec: tp.Optional[str], conv: tp.Optional[str], ) -> None: """Update tokens list in-place""" if idx < len(self.tokens): tok = self.tokens[idx] self.tokens[idx] = _ParsedToken(_format_value(val, spec, conv), tok.field)
[docs]def prompt_tokens_formatter_default(container: ParsedTokens) -> str: """ Join the tokens Parameters ---------- container: ParsedTokens parsed tokens holder Returns ------- str process the tokens and finally return the prompt string """ return "".join([tok.value for tok in container.tokens])
[docs]class PromptFormatter: """Class that holds all the related prompt formatting methods, uses the ``PROMPT_FIELDS`` envvar (no color formatting). """ def __call__(self, template=DEFAULT_PROMPT, fields=None, **kwargs) -> str: """Formats a xonsh prompt template string.""" if fields is None: self.fields = XSH.env["PROMPT_FIELDS"] # type: ignore else: self.fields = fields # some quick tests if isinstance(fields, dict): pflds: "PromptFields[PromptField]" = PromptFields(XSH, init=False) pflds.update(fields) self.fields = pflds try: toks = self._format_prompt(template=template, **kwargs) prompt = toks.process() except Exception as ex: # make it obvious why it has failed import logging logging.error(str(ex), exc_info=True) xt.print_exception( f"Failed to format prompt `{template}`-> {type(ex)}:{ex}" ) return _failover_template_format(template) return prompt def _format_prompt(self, template=DEFAULT_PROMPT, **kwargs) -> ParsedTokens: tmpl = template() if callable(template) else template toks = [] for literal, field, spec, conv in xt.FORMATTER.parse(tmpl): if literal: toks.append(_ParsedToken(literal)) entry = self._format_field(field, spec, conv, idx=len(toks), **kwargs) if entry is not None: toks.append(_ParsedToken(entry, field)) return ParsedTokens(toks, template) def _format_field(self, field, spec="", conv=None, **kwargs): if field is None: return elif field.startswith("$"): val = XSH.env[field[1:]] return _format_value(val, spec, conv) elif field in self.fields: val = self._get_field_value(field, spec=spec, conv=conv, **kwargs) return _format_value(val, spec, conv) else: # color or unknown field, return as is return "{" + field + "}" def _get_field_value(self, field, **_): try: return self.fields.pick(field) except Exception: # noqa print("prompt: error: on field {!r}" "".format(field), file=sys.stderr) xt.print_exception() value = f"{{BACKGROUND_RED}}{{ERROR:{field}}}{{RESET}}" return value
[docs]def default_prompt(): """Creates a new instance of the default prompt.""" if xp.ON_CYGWIN or xp.ON_MSYS: dp = ( "{env_name}" "{BOLD_GREEN}{user}@{hostname}" "{BOLD_BLUE} {cwd} {prompt_end}{RESET} " ) elif xp.ON_WINDOWS and not xp.win_ansi_support(): dp = ( "{env_name}" "{BOLD_INTENSE_GREEN}{user}@{hostname}{BOLD_INTENSE_CYAN} " "{cwd}{branch_color}{curr_branch: {}}{RESET} " "{BOLD_INTENSE_CYAN}{prompt_end}{RESET} " ) else: dp = ( "{env_name}" "{BOLD_GREEN}{user}@{hostname}{BOLD_BLUE} " "{cwd}{branch_color}{curr_branch: {}}{RESET} " "{RED}{last_return_code_if_nonzero:[{BOLD_INTENSE_RED}{}{RED}] }{RESET}" "{BOLD_BLUE}{prompt_end}{RESET} " ) return dp
def _failover_template_format(template): if callable(template): try: # Exceptions raises from function of producing $PROMPT # in user's xonshrc should not crash xonsh return template() except Exception: xt.print_exception() return "$ " return template @xt.lazyobject def RE_HIDDEN(): return re.compile("\001.*?\002")
[docs]def multiline_prompt(curr=""): """Returns the filler text for the prompt in multiline scenarios.""" line = curr.rsplit("\n", 1)[1] if "\n" in curr else curr line = RE_HIDDEN.sub("", line) # gets rid of colors # most prompts end in whitespace, head is the part before that. head = line.rstrip() headlen = len(head) # tail is the trailing whitespace tail = line if headlen == 0 else line.rsplit(head[-1], 1)[1] # now to construct the actual string dots = XSH.env.get("MULTILINE_PROMPT") dots = dots() if callable(dots) else dots if dots is None or len(dots) == 0: return "" tokstr = xt.format_color(dots, hide=True) baselen = 0 basetoks = [] for x in tokstr.split("\001"): pre, sep, post = x.partition("\002") if len(sep) == 0: basetoks.append(("", pre)) baselen += len(pre) else: basetoks.append(("\001" + pre + "\002", post)) baselen += len(post) if baselen == 0: return xt.format_color("{RESET}" + tail, hide=True) toks = basetoks * (headlen // baselen) n = headlen % baselen count = 0 for tok in basetoks: slen = len(tok[1]) newcount = slen + count if slen == 0: continue elif newcount <= n: toks.append(tok) else: toks.append((tok[0], tok[1][: n - count])) count = newcount if n <= count: break toks.append((xt.format_color("{RESET}", hide=True), tail)) rtn = "".join(itertools.chain.from_iterable(toks)) return rtn
[docs]def is_template_string(template, PROMPT_FIELDS=None): """Returns whether or not the string is a valid template.""" template = template() if callable(template) else template try: included_names = {i[1] for i in xt.FORMATTER.parse(template)} except ValueError: return False included_names.discard(None) if PROMPT_FIELDS is None: fmtter = XSH.env.get("PROMPT_FIELDS", PROMPT_FIELDS) else: fmtter = PROMPT_FIELDS known_names = set(fmtter.keys()) return included_names <= known_names
def _format_value(val, spec, conv) -> str: """Formats a value from a template string {val!conv:spec}. The spec is applied as a format string itself, but if the value is None, the result will be empty. The purpose of this is to allow optional parts in a prompt string. For example, if the prompt contains '{current_job:{} | }', and 'current_job' returns 'sleep', the result is 'sleep | ', and if 'current_job' returns None, the result is ''. """ if val is None or (isinstance(val, BasePromptField) and val.value is None): return "" val = xt.FORMATTER.convert_field(val, conv) if spec: val = xt.FORMATTER.format(spec, val) if not isinstance(val, str): val = format(val) return val
[docs]class PromptFields(tp.MutableMapping[str, "FieldType"]): """Mapping of functions available for prompt-display.""" def __init__(self, xsh: "XonshSession", init=True): self._items: "dict[str, str | tp.Callable[..., str]]" = {} self._cache: "dict[str, str|FieldType]" = {} """for callbacks this will catch the value and should be cleared between prompts""" self.xsh = xsh if init: self.load_initial() def __repr__(self): return f"{self.__class__.__module__}.{self.__class__.__name__}(...)" def _repr_pretty_(self, p, cycle): name = f"{self.__class__.__module__}.{self.__class__.__name__}" with p.group(1, name + "(", ")"): if cycle: p.text("...") elif len(self): p.break_() p.pretty(dict(self)) def __getitem__(self, item: "str|BasePromptField"): # todo: load on-demand from modules if isinstance(item, BasePromptField): item = item.name return self._items[item] def __delitem__(self, key): del self._items[key] def __iter__(self): yield from self._items def __len__(self): return len(self._items) def __setitem__(self, key, value): self._items[key] = value
[docs] def get_fields(self, module): """Find and load all instances of PromptField from the given module. Each module is expected to have a single prompt-field with the same name as the module """ mod_name = module.__name__.replace(module.__package__, "", 1).replace( ".", "", 1 ) for attr, val in vars(module).items(): if isinstance(val, BasePromptField): if attr == mod_name: name = attr else: name = f"{mod_name}.{attr}" val.name = name yield val
[docs] def load_initial(self): from xonsh.prompt import gitstatus from xonsh.prompt.cwd import ( _collapsed_pwd, _dynamically_collapsed_pwd, _replace_home_cwd, ) from xonsh.prompt.env import env_name, vte_new_tab_cwd from xonsh.prompt.job import CurrentJobField from xonsh.prompt.times import _localtime from xonsh.prompt.vc import branch_bg_color, branch_color, current_branch self.update( dict( user=xp.os_environ.get( "USERNAME" if xp.ON_WINDOWS else "USER", "<user>" ), prompt_end="#" if xt.is_superuser() else "$", hostname=socket.gethostname().split(".", 1)[0], cwd=_dynamically_collapsed_pwd, cwd_dir=lambda: os.path.join(os.path.dirname(_replace_home_cwd()), ""), cwd_base=lambda: os.path.basename(_replace_home_cwd()), short_cwd=_collapsed_pwd, curr_branch=current_branch, branch_color=branch_color, branch_bg_color=branch_bg_color, current_job=CurrentJobField(name="current_job"), env_name=env_name, env_prefix="(", env_postfix=") ", vte_new_tab_cwd=vte_new_tab_cwd, time_format="%H:%M:%S", localtime=_localtime, last_return_code=lambda: XSH.env.get("LAST_RETURN_CODE", 0), last_return_code_if_nonzero=lambda: XSH.env.get("LAST_RETURN_CODE", 0) or None, ) ) for val in self.get_fields(gitstatus): self[val.name] = val
[docs] def pick(self, key: "str|FieldType") -> "str | FieldType | None": """Get the value of the prompt-field Notes ----- If it is callable, then the result of the callable is returned. If it is a PromptField then it is updated """ name = key if isinstance(key, str) else key.name if name not in self._items: return None value = self._items[name] if name not in self._cache: if isinstance(value, BasePromptField): value.update(self) elif callable(value): value = value() # store in cache self._cache[name] = value return self._cache[name]
[docs] def pick_val(self, key): """wrap .pick() method to get .value attribute in case of PromptField""" val = self.pick(key) return val.value if isinstance(val, BasePromptField) else val
[docs] def needs_calling(self, name) -> bool: """check if we can offload the work""" if name in self._cache or (name not in self._items): return False value = self[name] return isinstance(value, BasePromptField) or callable(value)
[docs] def reset(self): """the results are cached and need to be reset between prompts""" self._cache.clear()
[docs] def reset_key(self, key): """remove a single key from the cache (if it exists)""" self._cache.pop(key, None)
[docs]class BasePromptField: value = "" """This field should hold the bare value of the field without any color/format strings""" _name: "str|None" = None updator: "tp.Callable[[FieldType, PromptFields], None] | None" = None """this is a callable that needs to update the value or any of the attribute of the field""" def __init__( self, **kwargs, ): """ Parameters ---------- kwargs attributes of the class will be set from this """ for attr, val in kwargs.items(): setattr(self, attr, val)
[docs] def update(self, ctx: PromptFields) -> None: """will be called from PromptFields getter for each new prompt""" if self.updator: self.updator(self, ctx)
def __format__(self, format_spec: str): return format(self.value, format_spec) def __bool__(self): return bool(self.value) def __repr__(self): return f"<Prompt: {self._name}>"
[docs] @classmethod def wrap(cls, **kwargs) -> "tp.Callable[..., FieldType]": """decorator to set the updator""" def wrapped(func): return cls(updator=func, **kwargs) return wrapped
@property def name(self) -> str: """will be set during load. Notes ----- fields with names such as ``gitstatus.branch`` mean they are defined in a module named ``gitstatus`` and are most likely a subfield used by ``gitstatus`` """ if self._name is None: raise NotImplementedError("PromptField name is not set") return self._name @name.setter def name(self, value: str) -> None: self._name = value
[docs]class PromptField(BasePromptField): """Any new non-private attributes set by the sub-classes are considered a way to configure the format""" # these three fields will get updated by the caller prefix = "" suffix = "" def __format__(self, format_spec: str): if self.value: return self.prefix + format(self.value, format_spec) + self.suffix return ""
[docs]class MultiPromptField(BasePromptField): """Facilitate combining other PromptFields""" separator = "" """in case this combines values from other prompt fields""" fragments: "tuple[str, ...]" = () """name of the fields or the literals to combine. If the framgment name startswith ``.`` then they are resolved to include the name of this field.""" def __init__(self, *fragments: "str", **kwargs): super().__init__(**kwargs) self.fragments = fragments or self.fragments
[docs] def get_frags(self, env): yield from self.fragments
def _collect(self, ctx): for frag in self.get_frags(ctx.xsh.env): if frag.startswith("."): field_name = f"{self.name}{frag}" if field_name in ctx: frag = field_name if frag in ctx: yield format(ctx.pick(frag)) elif isinstance(frag, str): yield frag
[docs] def update(self, ctx: PromptFields): self.value = self.separator.join(self._collect(ctx))